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Measuring & Mapping

Where, how far, and how much? People have invented an astonishing array of devices to answer seemingly simple questions like these. Measuring and mapping objects in the Museum's collections include the instruments of the famous—Thomas Jefferson's thermometer and a pocket compass used by Meriwether Lewis and William Clark on their expedition across the American West. A timing device was part of the pioneering motion studies of Eadweard Muybridge in the late 1800s. Time measurement is represented in clocks from simple sundials to precise chronometers for mapping, surveying, and finding longitude. Everyday objects tell part of the story, too, from tape measures and electrical meters to more than 300 scales to measure food and drink. Maps of many kinds fill out the collections, from railroad surveys to star charts.

From its infancy, timekeeping has depended on astronomy. The motion of celestial bodies relative to the rotating Earth provided the most precise measure of time until the mid-twentieth century, when quartz and atomic clocks proved more constant. Until that time, mechanical observatory clocks were set and continuously corrected to agree with astronomical observations.

The application of electricity to observatory timepieces in the late 1840s revolutionized the way American astronomers noted the exact movement of celestial events. U.S. Coast Survey teams devised a method to telegraph clock beats, both within an observatory and over long distances, and to record both the beats and the moment of observation simultaneously. British astronomers dubbed it the "American method of astronomical observation" and promptly adopted it themselves.

Transmitting clock beats by telegraph not only provided astronomers with a means of recording the exact moment of astronomical observations but also gave surveyors a means of determining longitude. Because the Earth rotates on its axis every twenty-four hours, longitude and time are equivalent (fifteen degrees of longitude equals one hour).

In 1849 William Cranch Bond, then director of the Harvard College Observatory, devised an important improvement for clocks employed in the "American method." He constructed several versions of break-circuit devices—electrical contracts and insulators attached to the mechanical clock movement—for telegraphing clock beats once a second. The Bond regulator shown here incorporates such a device. Bond's son Richard designed the accompanying drum chronograph, an instrument that touched a pen to a paper-wrapped cylinder to record both the beats of the clock and the instant of a celestial event, signaled when an observer pressed a telegraph key.

This is an example of the "new theodolate" for which Rowland Houghton (about 1678-1744), a Boston mechanic, received a patent from the General Court of the Colony of Massachusetts in 1735. This was the second patent for a mechanical invention issued in the British colonies of North America. The patent did not describe Houghton's instrument, but stated simply that it was designed "for surveying of lands, with suitable instruments, with greater ease and dispatch than any surveying instrument heretofore projected or made within this province." The only other contemporary reference to this instrument appears in Houghton's 1737 advertisement for aqueducts, which states that "Said Houghton has lately improv'd on his new Theodolate (sic), by which the art of Surveying is rendered more plain & easy than heretofore."

The horizontal circle is graduated to degrees and numbered in quadrants. One side is also numbered from VI to XII to VI, as for a sundial. The sight vanes for the alidade are missing. The compass card—marked "J. R. LINCOLN, BOSTON”—is a 19th-century replacement.

When the Smithsonian acquired this instrument, it was the only known surviving example. Another example, however, has recently come to light.

During the Civil War Army physician Dr. G. D. O'Farrell received this watch as a gift from grateful patients.

In the 1850s watchmakers at what would become the American Watch Company of Waltham, Massachusetts, developed the world's first machine-made watches. They completely redesigned the watch so that its movement could be assembled from interchangeable parts made on specialized machines invented just for that purpose. They also developed a highly organized factory-based work system to speed production and cut costs.

In its first decade, the firm's work was largely experimental and the firm's finances were unsteady. The name of the company changed repeatedly as investors came and went. Operations moved from Roxbury to Waltham in 1854, and the Panic of 1857 brought bankruptcy and a new owner, Royal Robbins. Reorganization and recovery began, and output reached fourteen thousand watches in 1858.

Renamed the American Watch Company the next year, the firm was on the brink of success from an unexpected quarter. During the Civil War, Waltham's watch factory designed and mass-produced a low-cost watch, the William Ellery model. Selling for an unbelievable $13.00, these watches became a fad with Union soldiers. Just as itinerant peddlers had aroused the desire for inexpensive clocks, roving merchants sold thousands of cheap watches to eager customers in wartime encampments. By 1865, the year the war ended, William Ellery movements represented almost 45 per cent of Waltham's unit sales.

This William Ellery model watch was a gift to Army surgeon G. D. O'Farrell from his patients at White Hall, a Civil War hospital near Philadelphia. The inscription on the dust cover of O'Farrell's watch reads: "White Hall USA Gen'l Hospital, Feb. 15, 1865 Presented to Dr. G. D. O'Farrell, USA by the patients of Ward C as a token of regard & respect for his ability as a surgeon and unswerving integrity as a man."

This compass has a heavy brass bowl gimbal mounted in a wooden box and a flat card with central buoyancy. The inscriptions read "E. S. RITCHIE BOSTON 23924" and "PATENTED" and "RITCHIE, BOSTON U.S.A." The Ritchie ledgers, now held by Ritchie Navigation, indicate that it was made on May 7, 1898, and sold to T.S. & J.D. Negus, a New York firm that sold a variety of nautical and optical instruments.

This octant has a rosewood frame, flat brass index arm, and ivory name plate. The ivory scale is graduated every 20 minutes from -5° to +95° and read by vernier to single minutes of arc. The "Andw Newell Maker Boston" inscription refers to Andrew Newell (1751-1798), a mathematical instrument maker in Boston. Inside the box is the trade card of David Baker, proprietor of a nautical instrument shop in New Bedford during the second quarter of the nineteenth century.

This compass has a turned wooden bowl gimbal mounted in a wooden box. The inscription reads "S. THAXTER MAKER No 27 STATE STREET BOSTON." It was made between 1813 when S. Thaxter moved to No. 27 State Street, and 1822 when the firm became S. Thaxter & Son. The donor believed that it had belonged to his distant ancestor, Simon Mellon, and was used in a whaling vessel in the Bering Sea.

This compass has a turned wooden bowl gimbal mounted in a wooden box. It probably dates from the middle decades of the nineteenth century. The inscription reads "C. R. SHERMAN & Co. NEW BEDFORD." Charles R. Sherman (fl. 1865-1905) sold instruments and other items for nautical use.

This instrument is a specialized timekeeper originally designed for finding longitude at sea and later used everywhere as a source of portable precise time. It has an English-made chronometer movement, finished by the firm William Bond & Son of Boston and fitted with the Bond break-circuit device, electrical equipment to permit the telegraphing of time signals. The Smithsonian’s Astrophysical Observatory used the instrument. The chronometer’s wooden box fits into a padded basket for extra protection.

From its infancy, timekeeping has depended on astronomy. The motion of celestial bodies relative to the rotating Earth provided the most precise measure of time until the mid-twentieth century, when quartz and atomic clocks proved more constant. Until that time, mechanical observatory clocks were set and continuously corrected to agree with astronomical observations.

The application of electricity to observatory timepieces in the late 1840s revolutionized the way American astronomers noted the exact movement of celestial events. U.S. Coast Survey teams devised a method to telegraph clock beats, both within an observatory and over long distances, and to record both the beats and the moment of observation simultaneously. British astronomers dubbed it the "American method of astronomical observation" and promptly adopted it themselves.

Transmitting clock beats by telegraph not only provided astronomers with a means of recording the exact moment of astronomical observations but also gave surveyors a means of determining longitude. Because the Earth rotates on its axis every twenty-four hours, longitude and time are equivalent (fifteen degrees of longitude equals one hour).

In 1849 William Cranch Bond, then director of the Harvard College Observatory, devised an important improvement for clocks employed in the "American method." He constructed several versions of break-circuit devices—electrical contracts and insulators attached to the mechanical clock movement—for telegraphing clock beats once a second. The Bond regulator shown in the forground incorporates such a device. Bond's son Richard designed the accompanying drum chronograph, an instrument that touched a pen to a paper-wrapped cylinder to record both the beats of the clock and the instant of a celestial event, signaled when an observer pressed a telegraph key.

In the 19th century, portable marine timekeepers called chronometers became indispensable instruments for determining longitude at sea. To use a marine chronometer, outbound sailors would set their timepieces to the time of a known port's longitude—say Greenwich, England, or Boston. Once at sea, mariners calculated their position east or west of that place by converting the difference in time on the chronometer and local ship time into distance, 15 degrees of longitude for every hour.

Tradition says this timekeeper was the first seagoing chronometer made in America. Twenty-three-year-old Boston clockmaker William Cranch Bond constructed it during the War of 1812. When Bond made his instrument, no chronometer industry existed in the United States, and British makers dominated the world market.

Bond's instrument went to sea only once, on a voyage to Sumatra in 1818 aboard the U.S. Navy vessel Cyrus. Chronometers were uncommon aboard American ships at the time, and the Cyrus's captain warned Bond to read the record of the instrument's performance with a critical eye.

Invented half a century earlier by John Harrison in England and Pierre LeRoy and Ferdinand Berthoud in France, the chronometer by Bond's time had already assumed standard features. Most of the chronometers ran from the force of an unwinding spring and had a special feature—the detent escapement. Suspended from gimbals in a wooden box, the instrument remained horizontal even on a heaving ship. Bond's timekeeper was different. Unable or unwilling to get British spring steel in wartime, he borrowed an 18th-century Berthoud design and built his timekeeper to run with power from a falling weight.

William Bond & Son, a family firm begun by William Cranch Bond's father in 1793, became one of America's best-known chronometer dealers. As the business flourished, the younger Bond pursued his passion for astronomy. In 1839 he became the first director of the Harvard College Observatory.